首页
-
2023.12.26
The “Missing baryons” in the cosmic web—what is it? Where is it? How much?
<p>Previous studies of galaxy formation have shown that only 10 per cent of the cosmic baryons are in stars and galaxies, while 90 per cent of them are missing. In this talk, I will present several observational studies that coherently find significant evidences of the missing baryons. The first measurement is the cross-correlation between the thermal Sunyaev-Zeldovich effect with gravitational le...</p>
详情 -
2023.11.14
The star formation, dust, and abundance of galaxies with CIB cross-correlations
<p>The cosmic infrared background (CIB) is the accumulated infrared radiation mainly generated from dust emissions in star-forming galaxies. It bears rich information about star formation history, dust thermodynamics, and galaxy abundance in the distant Universe. The CIB auto- and cross-correlations with other large-scale structure (LSS) tracers have been used to probe the star formation, dust, an...</p>
详情 -
2023.11.21
A two-phase model of galaxy formation: the growth of galaxies and supermassive black holes
<p>I will describe a model for galaxy formation and the growth of supermassive black holes (SMBHs), based on the fact that cold dark matter halos form their gravitational potential wells through a fast phase with rapid change in the potential, and that the high universal baryon fraction makes cooled gas in halos self-gravitating and turbulent before it can form rotation-supported disks. Gas fragme...</p>
详情 -
2023.10.31
Surveying galaxy clusters in the X-ray Universe: New results from eROSITA
<p>The eROSITA X-ray telescope has performed four X-ray all-sky surveys since its launch in July 2019. In this talk, I will briefly overview eROSITA's early results on galaxy clusters, with an emphasis on the eFEDS PV-phase program. I will also report the latest progress on clusters and superclusters from the first eROSITA All-Sky Survey.BIODr. Ang Liu is a postdoc researcher at Max Planck Institu...</p>
详情 -
2023.10.30
Cluster Intrinsic Alignment in DES Y1
<p>Clusters of galaxies trace the most non-linear peaks in the cosmic density field. The weak gravitational lensing of background galaxies by clusters can allow us to infer their masses. However, galaxies associated with the local environment of the cluster can also be intrinsically aligned due to the local tidal gradient, contaminating any cosmology derived from the lensing signal. In this talk, ...</p>
详情 -
2023.10.24
Optimization of Cosmological Information Extraction with Minkowski Functionals
<p>Galaxy survey provides an important window for the exploration of fundamental physics by accurately mapping the large-scale structure of the Universe (LSS), which is expected to lead to great scientific discoveries. In cosmology, LSS encodes abundant key cosmological information (e.g., baryon acoustic oscillations, neutrino masses, primordial non-Gaussianities, gravity properties, and cosmologi...</p>
详情 -
2023.10.17
existing tensions in ΛCDM model
<p>The concordance or standard Λ Cold Dark Matter (ΛCDM) model is a well-defined, predictive and simple cosmological model. A number of challenges of the standard ΛCDM model have been emerging during the past few years, which has been summarized by recent reviews.In this talk, I will give a brief introduction to several existing signals in cosmological and astrophysical data that appear to be i...</p>
详情 -
2023.10.10
Obstacles from interstellar matter and distortion for warp drive travel
<p>We investigate obstacles of superluminal “warp drive” travels from interactions with interstellar matter and from curvature effects. The effect of collision of interstellar dust particles and photons with the spacecraft will all lead to a pressure proportional to the apparent velocity of the spaceship vs. The force exerted on the spacecraft from the curvature effect has two non-trivial compon...</p>
详情 -
2023.09.26
Implication of UV variability for the abundance of bright galaxies at cosmic dawn 紫外光度波动对宇宙黎明时明亮星系丰度的影响
<p>The JWST has uncovered a large population of UV-bright galaxies at redshifts above ~10, which surpasses the predictions from a range of theoretical models developed based on lower redshift galaxies. While various solutions have been proposed focusing on systematically increasing the UV photon yield in high-redshift galaxies, I will discuss in this talk an alternate solution from UV variability....</p>
详情 -
2023.09.19
Yan Liang and Ruizhe Feng
<p>Speaker: Yan LiangTitle: Lensing, Dynamics & Mass Distribution of the Early-Type GalaxyAbstract:The mass structure, as one of the most important properties of early-type galaxy, is associated with the galactic formation and evolution. Nowadays, the gravitational lensing at the galaxy scale and dynamics information of the galaxy have been widely used to constrain the galaxy mass structure. In th...</p>
详情